Make it work without esModuleInterop: true in tsconfig.json

Libraries should not force users to enable esModuleInterop in tsconfig.json.

See this discussion: https://github.com/apollographql/apollo-server/issues/1977#issuecomment-683235089

I’ve fixed the d.ts file to work with and without esModuleInterop: true.

The existing TypeScript code would work without any changes.

The followings are the testing codes to ensure backward compatibility:

Current: https://github.com/umireon/atlassian-connect-express-esModuleInterop/tree/main

With esModuleInterop: true : https://github.com/umireon/atlassian-connect-express-esModuleInterop/tree/with-tsconfig